Sleep disorders which affect breathing are characterized by repetitive episodes of reduced breathing during sleep. Obstructive Sleep Apnea (OSA), for example, results in episodes of intermittent cessation of airflow, with each episode typically lasting 10 seconds or more. These interruptions in airflow occur when the tongue and other soft tissue of the nasopharynx and oropharynx are affected by the flow of air through the upper airway, as well as by the low pressure generated by the respiratory effort of the patient. In patients with OSA, such effects are relatively large, and result in a partial or complete blockage of the flow of air through the upper airway. These blockages lead to a drop in oxygen supply to the blood, which eventually wakes the patient, after which normal respiration is resumed. Typically, once the patient falls back asleep, the process of airway blockages and waking repeats. Such repetition often continues periodically throughout sleep, in some cases averaging 60 or more episodes per hour of sleep, having consequentially devastating effects on the health and well-being of the patient.
One family of techniques developed to treat sleep apnea uses compressors and facial masks to maintain patient respiratory pressure support with continuous positive airway pressure (CPAP) during sleep. Such techniques are typically implemented with devices known as CPAP machines. Although CPAP machines are highly effective in treating sleep apnea, they are cumbersome to the patient, requiring the patient to wear the CPAP machine mask throughout sleep. Furthermore, patient mobility during sleep is limited by a hose which connects the CPAP mask to the compressor. Additionally, the positive air pressure in the upper airways is very uncomfortable, and often leads to flu-like and other side effects.
Alternative techniques are currently in development, which rely on devices that are surgically implanted in tissue in the mouth of the patient to reduce the effects that cause apnea episodes. However, these techniques are far from being commercial and may pose hygienic liabilities. Non-surgical techniques rely on inserting mouth pieces which move the lower jaw forward thus opening an airway behind the tongue, but these devices are not very effective. Other intra-oral devices, having permanently deployed stents or tongue retaining protrusions for reducing upper airway obstructions have been tried, but failed commercially, because such stents have negative physiological effects on the patient, as insertion of a deployed stent into the mouth stimulates the gag reflex and causes general discomfort. Such negative physiological effects can also devolve into negative psychological effects, as patients become wary of inserting devices into the mouth which will trigger the gag reflex.